Ink jet ink which is rub resistant to alcohol

ABSTRACT

Disclosed are a jet ink composition and a method for printing on glass, plastic, and metal surfaces messages having good adhesion and isopropyl alcohol rub resistance, said composition comprising an organic solvent, a flexible thermoplastic urethane resin, a colorant, a cellulose nitrate resin, and an adhesion promoter.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to ink jet printing compositions forprinting on non-porous substrates, particularly for printing onnon-porous substrates such as metal, glass, and plastic containers, thejet printing composition having the characteristics of fast drying, goodadhesion, and resistance to isopropyl alcohol rubs.

BACKGROUND OF THE INVENTION

Ink jet printing is a well-known technique by which printing isaccomplished without contact between the printing device and thesubstrate on which the printed characters are deposited. Brieflydescribed, ink jet printing involves the technique of projecting astream of ink droplets to a surface and controlling the direction of thestream electronically so that the droplets are caused to form thedesired printed image on that surface. This technique of noncontactprinting is particularly well suited for application of Characters ontoirregularly shaped surfaces, including, for example, the bottom ofglass, metal, or plastic containers, used for holding cosmetic,pharmaceutical, liquor, and health care products.

Reviews of various aspects of ink jet printing can be found thesepublications: Kuhn et al., Scientific American, April, 1979, 162-178;and Keeling, Phys. Technol., 12(5), 196-303 (1981). Various ink jetapparatuses are described in the following U.S. Pat. Nos.: 3,060,429,3,298,030, 3,373,437, 3,416,153, and 3,673,601.

In general, an ink jet composition must meet certain rigid requirementsto be useful in ink jet printing operations. These relate to viscosity,resistivity, solubility, compatibility of components and wettability ofthe substrate. Further, the ink must be quick-drying and smearresistant, resist alcohol rubs, and be capable of passing through theink jet nozzle without clogging, and permit rapid cleanup of the machinecomponents with minimum effort.

Many of the surfaces on which ink jet printing is utilized arenon-porous. The ink used for these applications must adhere well to thenon-porous substrate and normally must be alcohol rub resistant. Many ofthe cosmetic, pharmaceutical, liquor, and health care products containalcohols, such as isopropyl alcohol. During the manufacture andtransportation of the products containing alcohol, there exists apossibility that the products may spill out of the containers and smearthe printing codes.

Several ink compositions known heretofore are not suitable for the aboveuse. For example, UK Patent Application GB 2,105,735 discloses a jet inkcomposition comprising an oil soluble dye-impregnated polyurethane latexdispersed in an aqueous medium.

U.S. Pat. No. 4,680,332 discloses a jet ink composition comprising awater insoluble polymer such as a polyacrylate dispersed in a liquidmedium, the polymer containing therein an oil soluble dye, and anonionic stabilizer permanently attached thereto.

U.S. Pat. No. 5,207,825 discloses a jet ink composition which comprisesan aqueous liquid vehicle, a colorant, and a polymeric additive which isa substituted bisphenol A derivative.

U.S. Pat. No. 5,080,716 discloses a jet ink composition comprising arecording agent, a liquid medium capable of dissolving or dispersing therecording agent, and a substituted benzene or toluene sulfonamidecompound.

U.S. Pat. No. 5,254,158 discloses an ink composition which comprises anaqueous liquid vehicle, a colorant, and an additive selected from thegroup consisting of amine alkoxylates, sorbitan monoester alkoxylates,alkylene oxide adducts of glycerin, and mixtures thereof.

U.S. Pat. Nos. 5,215,577 and 5,178,671 disclose jet ink compositionscomprising a recording agent and a liquid medium for dissolution ordispersion thereof, the recording agent being an aromatic sulfonateddiazo compound.

U.S. Pat. No. 5,131,949 discloses a jet ink composition including arecording agent, a liquid medium capable of dissolving or dispersing therecording agent, and a compound having an amide group.

U.S. Pat. No. 5,213,613 discloses a jet ink comprising a recording agentand a liquid medium capable of dissolving or dispersing the recordingagent therein, wherein the ink contains an imide compound and at leastone compound selected from the group consisting of urea, thiourea andderivatives thereof, and volatile alkaline compounds.

U.S. Pat. No. 4,692,188 discloses a process for the preparation of jetink compositions, comprising (1) dissolving in a water-immiscibleorganic solvent a polymer composition and an organic oil soluble dye;(2) adding an aqueous phase water surfactant mixture thereto; (3)affecting emulsification thereof; and (4) subsequently evaporating fromthe aforementioned mixture the solvent thereby resulting in an ink withthe dye trapped in the polymer particles suspended in the aqueous phase.The polymer compositions include polycarbonates, polystyrene,polymethacrylates and copolymers thereof.

U.S. patent application 08/121,296, filed Sep. 14, 1994, and assigned tothe same entity as the instant application, discloses an ink compositionfor use in drop-on-demand ink jet operations for printing on poroussubstrates such as paper and card board, which has low levels ofvolatile organic compounds and that is both non-teratogenic andnon-carcinogenic.

All of the water based jet ink compositions disclosed by the abovereferences are generally directed to ink compositions suitable forprinting on paper and are not considered suitable for printing on thecontainers which are non-porous. To obtain the necessary qualities ofbeing fast drying and demonstrating good adhesion, solvent-based inkmust be used. Therefore a need exists for a jet ink composition that issolvent-based, fast drying, and has good adhesion to non-porouscontainers and isopropyl alcohol rub resistance. The ink should becapable of being printed onto glass, plastic, and metal surfaces withgood adhesion.

SUMMARY OF THE INVENTION

The present invention provides ink compositions that are capable ofadhering on glass, plastic, and metal container surfaces used for thepackaging of cosmetics, pharmaceuticals, liquor, and health careproducts and exhibits good adhesion and isopropyl alcohol rubresistance. The composition comprises an organic solvent, a flexiblethermoplastic polyurethane resin, a dye, a cellulose nitrate resin, andan adhesion promoter.

The present invention also provides a method of forming printed imageson the glass, plastic, and metal surfaces using the ink composition ofthe instant invention. In accordance with the present invention, themethod comprises projecting a stream of droplets of the ink compositiononto the surface of a substrate, such as glass, plastic and metal, andcontrolling the direction of the stream electronically so that thedroplets form the desired printed image on the surface.

The foregoing and other objects and advantages of the present invention,as well as additional inventive features, will be apparent from thedescription of the preferred embodiments of the invention providedherein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The jet ink composition of the instant invention comprises an organicsolvent, a dye, a polyurethane binder, a cellulose nitrate resin, and anadhesion promoter.

GENERAL PROPERTIES

In general, the ink compositions of the present invention exhibit thefollowing characteristics for use in ink jet printing systems: (1) aviscosity from about 1.6 to about 7.0 centipoises at 25° C.; (2) anelectrical resistivity from about 50 to about 2000 ohm-cm; and (3) asonic velocity from about 1100 to about 1300 meters/second.

Solvents

Organic solvents suitable for the ink composition of the instantinvention include ketones such as acetone, methyl ethyl ketone, diethylketone, cyclohexanone, and the like, esters such ethyl acetate, propylacetate, butyl acetate, amylacetate, and the like, alcohols suchmethanol, ethanol, n-propanol, isopropanol, n-butanol, i-butanol,t-butanol, n-pentanol, n-hexanol, and the like, hydrocarbon solventssuch as hexane, cyclohexane, heptane, benzene, toluene, xylene, and thelike, glycols such as ethylene glycol, propylene glycol, glycerin,diethylene glycol, and the like, glycol ethers such as ethylene glycoldimethyl ether, ethylene glycol diethylether, cellosolve, diethyleneglycol dimethylether, diethylene glycol diethylether, and the like, andother solvents commonly known to one of ordinary skilled in the art.Methyl ethyl ketone is a preferred solvent. If desired, a mixture ofsolvents may be used. For example, a small amount of ethanol may beadded to methyl ethyl ketone solvent.

Filmcol Special Industrial Solvent C-2 from Shell Chemical Co. which is200 proof modified specially denatured alcohol (5% methanol) is apreferred solvent.

Polyurethanes

Flexible thermoplastic polyurethane resins are used as binders in thepreparation of the ink compositions of the instant invention. Flexiblethermoplastic urethanes are produced by the reaction of polyols anddiisocyanates. Examples of polyols include ethylene glycol, propyleneglycol, propanediol, butanediol, polyethylene glycol, polypropyleneglycol, polyethylene glycol adipate diol, polyethylene glycol succinatediol, polytetrahydrofuran diol, and the like. Examples of diisocyanatesinclude 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate,4,4,-diphenylmethane diisocyanate, hexamethylene diisocyanate, and thelike.

Polyurethanes having molecular weight in the range of about 5,000 toabout 50,000 are preferred and polyurethanes having molecular weight inthe range of about 20,000 to about 24,000 are even more preferred.

Examples of preferred urethane polymers that are useful in the presentinvention include, but are not limited to, the flexible thermoplasticpolyurethane solutions sold under the commercial name of Surkopak byKane International Corp., Rye, New York. A variety of grades ofpolyurethanes are sold under this name and include Surkopak 2135,Surkopak 5299, Surkopak 5244, Surkopak 5255, Surkopak 2X, Surkopak 5322,Surkopak 5311, and Surkopak XL. They are normally used to modifynitrocellulose based printing inks for flexo and gravure applications onflexible packaging substrates such as polyethylene, polypropylene,polyester, and cellulose. The physical properties of the polyurethanesolutions are presented in Table 1 below.

                                      TABLE 1                                     __________________________________________________________________________    Properties of the Surkopak Polyurethane Resins                                Grade   2135                                                                              5299                                                                              5244*                                                                             5255                                                                              2X  5322**                                                                            5311                                                                              XL                                        __________________________________________________________________________    Solids %                                                                              80-85                                                                             80-85                                                                             73-78                                                                             73-78                                                                             65-70                                                                             68-73                                                                             63-68                                                                             68-73                                     Viscosity                                                                             15-25                                                                             25-30                                                                             12-16                                                                             25-30                                                                             40-50                                                                             6-8 30-40                                                                             15-20                                     Solvent A   A   E   E   E   E/A E   E/A                                       Flash Point, °C.                                                               12  12  -4  -4  -4  -4  -4  -4                                        __________________________________________________________________________     A = Alcohol; E = Ester; E/A = Mixture of E and A                              *Weight Average Molecular Weight Range 18,000-22,000                          **Weight Average Molecular Weight Range 7,000-9,000                      

These polyurethanes are non-reactive and are essentially free ofisocyanate groups. Among these preferred polyurethane solutions, evenmore preferred is Surkopak 5244, Surkopak 5244 is sold as a solution inethyl acetate.

The concentration of the polyurethane resin (active ingredient) in theink composition is in the range of about 1 percent to about 12 percentby weight, preferably in the range of about 1 percent to about 6 percentby weight, and more preferably in the range of about 2 percent to about5 percent by weight. If the polyurethane is commercially sold as asolution, as in the case of Surkopak, the amount of the polyurethanesolution to be used to prepare the ink is calculated from theconcentration of the polyurethane in the solution.

Colorants

The ink composition comprises a colorant which is a dye that imparts thedesired color to the printed message. Any dye that may be dissolved inthe ink composition may be used in the instant invention. For instance,U.S. Pat. No. 5,254,158, and UK Patent Application GB 2,105,735 listseveral examples of dyes. All of these dyes and pigments may be used inthe instant invention. Examples of dyes applicable to the presentinvention include, but are not limited to, the yellow dyes such as C.I.Solvent Yellow 19 (C.I. 13900A), C.I. Solvent Yellow 21 (C.I. 18690),C.I. Solvent Yellow 61, C.I. Solvent Yellow 80, FD&C Yellow #5, YellowShade 16948, Acid Yellow 23, Levaderm Lemon Yellow (Mobay), Spirit FastYellow 3G, Aizen Spilon Yellow C-GNH (Hodagaya Chemical Co.), PergasolYellow CGP (Ciba-Geigy), and the like, the orange dyes such as C.I.Solvent Orange 1 (C.I. 11920), C.I. Orange 37, C.I. Orange 40, DiaresinOrange K (Mitsubishi Chemical Industries, Ltd.), Diaresin Orange G(Mitsubishi Chemical Industries, Ltd.), Sumiplast Orange 3G (SumitomoChemical Co., Ltd.), and the like, red dyes such as C.I. Solvent Red 8,C.I. Solvent Red 81, C.I. Solvent Red 82, C.I. Solvent Red 84, C.I.Solvent Red 100, Cibacron Brilliant Red 38-A (Aldrich Chemical Co.),Drimarene Brilliant Red E-6A (Pylam, Inc.), Acid Red 92, Reactive red 31(ICI America), and the like, pink dyes such as Diaresin Pink M(Mitsubishi Chemical Industries, Ltd.), Sumiplast Pink RFF (SumitomoChemical Co.), Direct Brill Pink B Ground Crude (Crompton & Knowles),and the like, violet dyes such as C.I. Solvent Violet 8, C.I. SolventViolet 21, Diaresin Violet (Mitsubishi), Diaresin Violet D, SumiplastViolet RR (Sumitomo), and the like, blue dyes such as C.I. Solvent Blue2, C.I. Solvent Blue 11, C.I. Solvent Blue 25, C.I. Solvent Blue 36,C.I. Solvent Blue 55, and the like, green dyes such as C.I. SolventGreen 3 and the like, brown dyes such as C.I. Solvent Brown 3 andDiaresin Brown A (Mitsubishi), and the like, black dyes such as ValifastBlack 3810 (Orient), C.I. Solvent Black 3, C.I. Solvent Black 5, C.I.Solvent Black 7, C.I. Solvent Black 22, C.I. Solvent Black 27, C.I.Solvent Black 29, Acid Black 123, and the like. A preferred colorant isValifast Black 3810.

The colorant is present in the ink composition in an amount required toproduce the desired contrast and readability. The colorant is preferablypresent in the range of about 2 percent to about 12 percent by weight,more preferably in the range of about 3 percent to about 9 percent byweight, and even more preferably in the range of about 4 percent toabout 6 percent by weight.

Surfactants

The jet ink composition may preferably contain a surfactant, which maybe anionic, cationic, nonionic, or amphoteric. Examples of anionicsurfactants are, but are not limited to, alkylbenzene sulfonates such asdodecylbenzene sulfonate, alkylnaphthyl sulfonates such as butyl ornonyl naphthyl sulfonate, dialkyl sulfosuccinates such as diamylsulfosuccinate, alcohol sulfates such as sodium lauryl sulfate, andperfluorinated carboxylic acids such as perfluorodecanoic acid andperfluorododecanoic acid. Nonionic surfactants include the alkylestersof polyethylene glycol, fatty acid esters of glycerol, fatty acid estersof glycol, and the like, and fluorochemical surfactants such as FC 430,FC 431, FC 740, FC 120, FC 248, FC 352, FC 396, FC 807, and FC 824,which are available from 3M Co. Cationic surfactants includealkylamines, amine oxides, amine ethoxylates, alkyl hydroxyalkylimidazolines, quaternary ammonium salts, and amphoteric surfactantsinclude the alkylbetaines, the amidopropylbetaines, and the like. Thesurfactant FC 430, which is a mixture of fluoroaliphatic polymericacrylate esters, is a preferred surfactant.

The solid surfactant made into solution may be present in the jet inkcomposition in the range of about 0.01 percent to about 0.2 percent byweight, preferably in the range of about 0.01 percent to about 0.1percent by weight, and more preferably in the range of about 0.01percent to about 0.05 percent by weight.

Other Resins

The jet ink composition may contain an additional resin to improve theahesion and solvent resistance. These resins include cellulose basedresins. Examples of cellulose based resins are cellulose acetate,cellulose propionate, cellulose butyrate, cellulose acetate-butyrate,ethyl cellulose, hydroxypropyl cellulose, and cellulose nitrate. Apreferred cellulose based resin is cellulose nitrate.

Cellulose nitrate is the reaction product of cellulose with nitric acid.Various grades of cellulose nitrate are characterized by the degree ofsubstitution by nitro groups of the hydroxyl groups of cellulose.Cellulose nitrates which are useful in the present invention include anyof a wide variety of cellulose nitrates including those which arecommercially available. Useful cellulose nitrates include the RS, AS,and SS type cellulose nitrates wetted by isopropyl alcohol, ethanol orwater sold by Hercules, Inc. The RS type cellulose nitrate has a nominaldegree of substitution which corresponds to a nitrogen content of about12%. The viscosity of a particular cellulose nitrate solution is relatedto its degree of polymerization. Cellulose nitrate resins of manydifferent degree of polymerization are available under the RS type. Thepreferred cellulose nitrate is the one with the viscosity of 15centipoises (for about 12.2% solution).

The resin may be present in the jet ink composition in the range ofabout 1 percent to about 10 percent by weight, preferably in the rangeof about 2 percent to about 8 percent by weight, and more preferably inthe range of about 3 percent to about 5 percent by weight.

Plasticizers

The jet ink composition may preferably contain a plasticizer. The typeof plasticizer selected should be compatible with the additional resinselected for inclusion in the composition. For cellulose nitrate resin,examples of plasticizers that are compatible and useful are adipic acidderivatives such as diisobutyl adipate, di-n-hexyl adipate, and thelike, azelaic acid derivatives such as bis(2-ethyl hexyl)azelate,benzoic acid derivatives such as diethyleneglycol dibenzoate, citricacid derivatives such as tri-n-butyl citrate, epoxy derivatives such asepoxidized soybean oil, bisphenol A diglycidylether, glycol derivativessuch as diethyleneglycol dipelargonate, glycolates such as methylphthalyl ethyl glycolate, hydrocarbons such as hydrogenated terphenyls,isophthalic acid esters such as di-2-ethylhexyl isophthalate, oleic acidderivatives such as butyl oleate, phosphoric acid derivatives such astributyl phosphate, tri-2-ethylhexyl phosphate, and the like, phosphonicacid derivatives such as chlorinated polyphosphonate (Phosgard C-22-R),phthalic acid derivatives such as dimethyl phthalate, dibutyl phthalate,and the like, adipic acid polyesters such as Paraplex G-40 (mol. wt.6,000), Santicizer 334F (mol. wt. 2,000), and the like, ricinoleic acidderivatives such as methyl ricinoleate, stearic acid derivatives such asn-butyl stearate, sulfonic acid derivatives such as(o,p)-toluenesulfonamide, N-ethyl-(o,p)-toluenesulfonamide,toluenesulfonamide-formaldehyde resin (Santolite MHP), and the like,tartaric acid derivatives such as dibutyl tartrate, terephthalic acidderivatives such as bis(2-ethylhexyl)terephthalate, and trimellitic acidderivatives such as tris(2-ethylhexyl)trimellitate. Other examples ofplasticizers that will be compatible with cellulose nitrate can befound, e.g., in Kirk-Othmer--Encyclopedia of Chemical Technology, vol.18, p. 111-183, 3rd edition (John-Wiley & Sons). A preferred plasticizerfor use in the instant invention is Santicizer 8, which is ano,p-mixture of N-ethyl-toluenesulfonamide, available from Monsanto Co.

The plasticizer may be present in the jet ink composition in the rangeof about 0.1 percent to about 3 percent by weight, preferably in therange of about 0.1 percent to about 2 percent by weight, and morepreferably in the range of about 0.5 percent to about 1.5 percent byweight.

Adhesion Promoters

The jet ink composition may preferably contain an adhesion promoter toimprove the adhesion of the jet ink to the substrate. Examples of theclasses of adhesion promoters that may be useful are transition metalorganates such as titanium organates, zirconium organates, hafniumorganates, and the like. Preferred organates are the titanium organatessold by DuPont Chemical Co. under the tradename of Tyzor titanates.Examples of Tyzor titanates include Tyzor TBT, which is titaniumtetra-n-butoxide, Tyzor TPT, which is titanium tri-isopropoxide, TyzorGBA, which is titanium diisopropoxide bis(2,4-pentanedionate), Tyzor LA,which is titanium ammoniumlactate, and Tyzor AA, which is titaniumacetylacetonate. A preferred Tyzor titanate for use in the instantinvention is Tyzor GBA. Some of the titanates are sold as solution in asuitable solvent.

The titanate (the active ingredient) may be present in the jet inkcomposition in the range of about 0.1 percent to about 5 percent byweight, preferably in the range of about 0.5 percent to about 3 percentby weight, and more preferably in the range of about 1 percent to about2 percent by weight.

Other Additives

The jet ink composition may contain in addition additives for adjustingthe viscosity, electrical resistivity, and the speed of evaporation. Thepreferred range of viscosity is about 1.5 centipoise to about 6.0centipoise. The preferred resistivity is about 500 ohm-cm to about 1500ohm-cm.

The compositions of the present invention may contain conductivityagents. If present, they usually are present in amounts of from about0.0 percent to about 2.0 percent. Examples of suitable conductivityagents include dimethylamine hydrochloride, diethylamine hydrochloride,lithium nitrate, and hydroxylamine hydrochloride. Sufficientconductivity is offered by the dye, Valifast Black 3810, in the presenceof the solvent used in the ink. Humectants may be used in theformulations. Humectants include glycerin, ethylene glycol, and thelike. Various, known viscosity modifying agents may be added, as needed,to adjust the viscosity of any given ink formulation.

The jet ink formulation may be prepared by any known methods. In onemethod, all the desired ingredients are combined in a mixer or a mixingvessel and mixed sequentially until a homogeneous solution is obtained.

The jet ink composition may be generally jet printed onto the surface ofa wet glass, plastic, and metal article such as a glass bottle, plasticbottle, or aluminum container. The jet ink of the instant invention maybe jet applied onto a variety of glasses, including soda-lime glasses,borosilicate glasses, alumino-silicate glasses, lead glasses, borateglasses, and the like. The above specified types of glass may contain acoating.

The jet ink composition may be jet applied onto plastic bottles orcontainers. The bottle or container may be made by any kind of plastic.Examples of plastics include polyethylene, polypropylene, PVC, nylons,polyesters such as PET, polycarbonate, polyacetals, polyacrylates,polyurethanes, polyethers, polystyrene, polyimides, and the like. Ifnecessary, these plastic containers may be pretreated, for example, byoxidation, corona treatment, plasma treatment, and the like, to preparethe surface for jet printing.

The jet ink composition may also be applied on metal containers. Anymetal container may be jet printed using the jet ink of the instantinvention. Examples of metal containers include containers made ofaluminum, steel, tin, copper, and the like. Certain containers may needto be pretreated, such as sandblasting, acid cleaning, and the like, toprepare the surface for jet printing.

All percentages expressed herein are percentages by weight, based on thetotal weight of the ink composition of the present invention, unlessotherwise indicated.

The following example further illustrates the present invention but, ofcourse, should not be construed as in any way limiting its scope.

EXAMPLE 1

A jet ink composition was prepared by employing the followingformulation:

    ______________________________________                                        Ingredient             Percent by weight                                      ______________________________________                                        Methyl ethyl ketone (Harcos)                                                                         61.2                                                   Filmcol (Shell)        20.0                                                   Nitrocellulose; RS type, 15 cps (Hercules)                                                           6.0                                                    Surkopak Polyurethane 5244                                                                           5.0                                                    Santicizer 8 (Monsanto)                                                                              1.0                                                    Tyzor GBA (DuPont)     1.5                                                    Valifast Black Dye 3810 (Orient)                                                                     5.0                                                    FC 430 10% in NEK (3M Co.)                                                                           0.3                                                                           100.0                                                  ______________________________________                                    

The above ink formulation was prepared and tested on a variety of metalcans. Printer runnability testing was also carried out. The jet inkperformed satisfactorily. The drying time was also satisfactory. Theprinted images had isopropyl alcohol rub resistance. The images werecapable of resisting at least 20 medium force rubs from an isopropylalcohol soaked cotton swab.

Images can be printed on glass, plastic, and metal surfaces using thejet ink composition of the instant invention by projecting a stream ofdroplets of the ink to the surface and controlling the direction of thestream electronically so that the droplets form the desired printedimage on the surface.

All of the references, including patents, patent applications, andpublications, cited herein are hereby incorporated in their entiretiesby reference.

While this invention has been described with an emphasis upon thepreferred embodiment, it will be obvious to those of ordinary skill inthe art that variations of the preferred embodiment may be used and thatit is intended that the invention may be practiced otherwise than asspecifically described herein.

Accordingly, this invention includes all modifications encompassedwithin the spirit and scope of the invention as defined by the followingclaims.

What is claimed is:
 1. A jet ink composition for printing on glass,plastic, and metal surfaces messages having good adhesion and isopropylalcohol rub resistance, said composition comprising an organic solvent,a flexible thermoplastic polyurethane resin, a dye, a cellulose nitrateresin, and an adhesion promoter, said composition having (1) a viscosityfrom about 1.6 to about 7.0 centipoises at 25° C.; (2) an electricalresistivity from about 50 to about 2000 ohm-cm; and (3) a sonic velocityfrom about 1100 to about 1300 meters/second.
 2. The jet ink compositionof claim 1, wherein said solvent comprises methyl ethyl ketone.
 3. Thejet ink composition of claim 2, wherein said solvent further comprisesethanol.
 4. The jet ink composition of claim 1, wherein said flexiblethermoplastic polyurethane resin comprises polypropylene glycol and4,4'-diphenylmethane diisocyanate.
 5. The jet ink composition of claim4, wherein said polyurethane resin has a weight average molecular weightin the range of 18,000 to 22,000.
 6. The jet ink composition of claim 5,wherein said polyurethane resin is present in the concentration range ofabout 2 percent to about 12 percent by weight of said composition. 7.The jet ink composition of claim 6, wherein said polyurethane resin ispresent in the concentration range of about 4 percent to about 6 percentby weight.
 8. The jet ink composition of claim 7, wherein said dye isC.I. Solvent Black
 29. 9. The jet ink composition of claim 8, whereinsaid dye is present in the range of about 3 to about 7 percent by weightof said composition.
 10. The jet ink composition of claim 9, whereinsaid composition further comprises a surfactant.
 11. The jet inkcomposition of claim 10, wherein said surfactant is a nonionicfluoroaliphatic polymeric acrylate ester and is present in the range offrom about 0.01 to about 0.2 percent by weight of said composition. 12.The jet ink composition of claim 11, wherein said composition furthercomprises a plasticizer.
 13. The jet ink composition of claim 12,wherein said plasticizer is N-ethyl (o, p)-toluenesulfonamide.
 14. Thejet ink composition of claim 13, wherein said plasticizer is present inthe range of about 0.1 percent to about 3 percent by weight.
 15. The jetink composition of claim 1, wherein said adhesion promoter is a titaniumorganate.
 16. The jet ink composition of claim 1, wherein said solventis selected from the group consisting of ketones, esters, alcohols,hydrocarbons, glycols, and combinations thereof.
 17. The jet inkcomposition of claim 1, wherein said cellulose nitrate resin has anitrogen content of about 12 percent.
 18. A jet ink composition forprinting on glass, plastic, and metal surfaces messages having goodadhesion and isopropyl alcohol rub resistance, said compositioncomprising an organic solvent, a flexible thermoplastic polyurethaneresin, a dye, a cellulose nitrate resin, and a titanium organate,wherein said organate is selected from the group consisting of titaniumtetra-n-butoxide, titanium triisopropoxide, titanium diisopropoxidebis(2,4-pentanedionate), titanium ammoniumlactate, and titaniumacetylacetonate.
 19. The jet ink composition of claim 18, wherein saidorganate is present in the range of from about 0.1 percent to about 5percent by weight of said jet ink composition.